妊娠期糖筛查时机的探讨

目的评价在不同孕周进行50 g葡萄糖负荷试验（glucose challenge test, GCT）对妊娠期糖尿病（gestational diabetes mellitus, GDM）和妊娠期糖耐量受损（gestational impaired glucose tolerance test, GIGT）的筛查效果. 方法对不同孕周的2000例孕妇进行50 g GCT,异常者再做正规糖耐量试验,确诊GDM或GIGT,并比较不同孕周妊娠期糖尿病或妊娠期糖耐量受损的诊断效果. 结果不同孕周进行50 g糖筛不影响GDM和GIGT最后诊断率,本研究GDM的发生率为4.75%（95/2000）,GIGT为5.51%（103/2000）.空腹进行50 g GCT阳性率和假阳性率均高于餐后1 h的50 g GCT,两组比较差异有统计学意义（P〈0.01）.在较早孕周初次进行GCT筛查,有助于早期发现GIGT和GDM.在GCT筛查推荐时期（孕24～28周）再进行一次50 g GCT,有助于提高GDM和GIGT的诊断率.对于GIGT血糖控制不满意者,必要时重做葡萄糖耐量试验以确诊是否发展为GDM.早期行50 g GCT组的剖宫产率和巨大儿发生率均低于孕24～28周筛查组. 结论对于GDM和GIGT的孕妇及时诊断与及时治疗,可以降低巨大儿和剖宫产率.

Appropriate time for 50 g oral glucose challenge test (50 g GCT) during pregnancy

Objective To evaluate the different effect of 50 g glucose challenge test (GCT) on screening the glucose intolerance at different gestational age. Methods Two thousand pregnant women were divided into 2 groups(1000 in each). Women in group A received 50 g GCT at 14 and 28 gestational weeks respectively and 75 g oral glucose tolerance test (OGTT) were performed in those cases with abnormal 50 g GCT. 50 g GCT was performed after fasting at 14 gestational weeks and repeated one hour after a meal at 28 gestational weeks. Women in group B were screened by 50 g GCT at 28 gestational weeks and followed by 75 g OGTT for those with abnormal 50 g GCT. The diagnostic effect of 50 g GCT for screening at different weeks of gestation with different ways was evaluated. Results (1)The rate of abnormal result of 50 g GCT was higher in fasting cases than that of cases testing after meal (15.6% vs 12.2%, P<0.01). (2)50 g GCT at 14 weeks of gestation was of benefit to early diagnosis of glucose intolerance. (3)Repeated 50 g GCT at 24~28 weeks of gestation was necessary for screening the GDM (3.1%) and GIGT (2.0%) for those who had positive 50 g GCT at 14 weeks. (4)Repeated OGTT was necessary for uncontrolled GIGT cases in order to reclassification (4 cases from GIGT to GDM). Conclusions 50 g GCT at 14 weeks of gestation allows for an earlier detection for GDM. The false positive rate is lower in 50 g GCT performed 1 h after meal than that of fasting 50 g GCT. 50 g GCT at 24~28 weeks of gestation is necessary for a second screening. Early diagnosis of glucose intolerance can improve the maternal and fetal outcomes.